The ratio of the speed of light in a vacuum to the speed of light in a material. The difference in refractive indices between the core and clad
of a fiber allows light to propagate down a fiber from transmitter to receiver.

The ratio of the speed of light in a vacuum to the speed of light in a material. The difference in refractive indices between the core and clad
of a fiber allows light to propagate down a fiber from transmitter to receiver.